The objectives of this renewal grant are to continue investigating the effects of alcohol on cognitive (memory) and perceptual-motor (choice reaction time) performance in human female subjects during the menstrual cycle and to evaluate the influence of oral contraceptives and other steroid hormone supplements on blood alcohol variables and performance measures. Six experiments have been proposed to fulfill these objectives. First females will continue to be tested during the menstrual flow period, the ovulatory period and the pre-menstrual period to examine possible difference in response to alcohol (0.66 ml/kg) at 0.04% on the ascending and descending limbs of the blood alcohol curve. Female subjects will be compared to male subjects to evaluate possible sex differences in response to alcohol. The second experiment is directed at evaluating our preliminary results that women taking oral contraceptives metabolize alcohol slower than women not taking oral contraceptives. The third study will evaluate performance and blood alcohol variables in 10 post-menopausal women and 10 women who have had a total hysterectomy. The effect of sex hormonal supplements will be evaluated on half of these women. A fourth study will involve administering alcohol for 30 days to five regularly menstruating women, five women taking oral contraceptives and five post-menopausal women and determining the relationship of plasma estrogen and progesterone levels to blood alcohol variables and reaction time performance throughout a complete menstrual cycle. The fifth study will determine if ethanol metabolism increases in a group of 10 women after they start taking oral contraceptives. The sixth study will be similar to the fourth experiment except alcohol will be given to 10 female alcoholics. The women will be tested for one complete menstrual cycle and plasma steroid levels will be measured. This constellation of experiments will provide information on the relationship between hormonal changes (days in the menstrual cycle, oral contraceptives, hormonal supplements) and performance of women during acute alcohol intoxication.